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This is laboratory is intended to get you up to speed quickly with both C++ and Unix.
Every week we will have a lab meeting. Each lab will consist of three parts: a pre-lab (to be completed by Tuesday at the due time listed on the lab due dates page, an in-lab (activity to be done during lab), and a post-lab. The pre-lab will typically also include a tutorial. Parts of all three of these may be required to turned in. The due dates are all listed on the lab due dates page. This will all be discussed in this lab.
Lab submission and in-lab extensions can be found through the Course Tools tab on Collab or directly at this link: https://libra.cs.virginia.edu/~pedagogy
Complete Tutorial 1: Introduction to UNIX. For this course, you will need to be familiar with Emacs. You are welcome to use any editor that is not an IDE (Integrated Development Environment), such as emacs, nano, or vim; you may be tested on the key bindings of your preferred editor. (Notepad doesn't count.)
Below is a sample function with a main() function that calls it. You may find this example helpful in writing your function to compute x^n and the main() function to call it.
#include <iostream>
using namespace std;
int foo (int a, int b) {
int tmp = a;
tmp += b;
return tmp;
}
int main( ) {
int x, y, z;
cin >> x;
cin >> y;
z = foo (x, y);
cout << x << " + " << y << " = " << z << endl;
return 0;
}For the pre-lab, you will need to write a recursive function called xton() to compute x^n for nonnegative integers n. Assume that x^0=1. Put this function in a program with a main() function. Your program should prompt the user for two integer values, and raise the first to the power of the second by calling your xton() function.
The file should be called xToN.cpp, and should be submitted to the pre-lab 1 assignment in the submission system.
Note that your program should take in exactly two inputs and nothing else. We are going to run it through an automated grading script prior to the TAs grading it -- if your program takes in a different number of inputs, you will receive points off.
Lastly, take a look at the object life-cycle code (lifecycle.cpp (src)). Use it as a mechanism for understanding how various aspects of C++ work. Compile and run the program (see part III of the tutorial). Try stepping through it by hand. Use the readings, the web, and any other C++ references to help you look up parts of the program you do not understand.
This section describes how to log into Linux in the lab room (either Olsson 001 or Rice 340). Although this is really part of the in-lab, you won't be able to access this document until you have logged in, which is why the directions are listed in the pre-lab section.
The machines in the lab room run Linux (the Ubuntu distribution). You have accounts on these machines, and the password should have been emailed to you.
Once the login screen appears, you can log in. Be aware that it may take a full minute to log you into the machine. Linux has a number of desktop environments that one can choose from -- each of these has a different look-and-feel, in the same way that Windows is different from Mac OS X. We are currently using KDE. To load up a terminal window, click on the button that looks like the Windows start button, and type in "konsole" into the search box.
When you are finished, you should log out (from the menu at the top, or you can hit Ctrl-Alt-Backspace), and reboot the computer (through the options menu at the bottom of the login screen).
The purpose of the labs is to allow you to work through the lab activity, and if you encounter questions or problems, ask for TA assistance. Note that each file you electronically submit (including text files!) should contain a header containing your name, email ID, file name, and the date.
All of the files required for this lab are listed above (in the Procedure section), and are also listed below.
The first thing you need to do is clone the github repo into your lab account. To do this, enter:
git clone https://github.com/markfloryan/pdr.gitThis will create a 'pdr' directory, which is the copy of the repo. Each week, you will need to update the repo with the current contents. To do so, cd into that 'pdr' directory, and enter:
git pullTo view the contents in a web browser, you should enter the following as the URL (replacing 'mst3k' with your userid):
file:///home/mst3k/pdr/readme-old.htmlNote that there are three forward slashes there!
We realize that you cannot view these directions until after you have the github repo cloned locally. So hopefully you read these ahead of time. Otherwise, the TAs will be able to help you with this part. The lab can also be viewed online at http://markfloryan.github.io/pdr/labs/lab01/index.html.
clang++ lifecycle.cpp) and execute the program.clang++ LifeCycle.cpp TestLifeCycle.cpp (you usually leave out the .h files when compiling). Add the descriptive header at the top of the file containing your identifying information, and name them as follows:
getMaxMyObj(). Recompile. What happens and why? Talk to TA if you are unsure. Now un-comment the prototype.clang++ svutil.cpp svtest.cpp will compile the program.#include <iostream> preprocessor directive in the file svtest.cpp, and then rebuild the program. Was there an error?using namespace std; in svutil.h, and rebuild the program. Was there an error? What objects are now undeclared and why?Does your program not compile? Here are a few things to try -- these are problems that previous students have encountered.
#include <iostream> at the beginning of each file (well, really each file that uses cin and cout, but it doesn't hurt to have it at the beginning of each file).using namespace std; at the beginning of each file.Under Windows, the case of a file name is ignored -- thus, lifecycle.cpp, LifeCycle.cpp, and LIFECYCLE.CPP all refer to the same file. However, it is NOT true for Linux, which is what we will use to test and grade your code. Thus, if your file is called 'LifeCycle.h', and you have (in your TestLifeCycle.cpp file) a line that states: #include "lifecycle.h", then your program will NOT work under Linux (since case DOES matter with file names). Since your code does not compile, you will get zero credit. So make sure your file names match!
All assignments will be submitted through our custom submission tool. These can be accessed through Collab, or directly at the link in the Procedure section of this lab.
Each assignment has 3 dates: an open date (when you can start submitting the assignment), a due date (when it's due), and a close date (the last point that you can submit the assignment). The dates are listed for the week of the lab (the lab week starts on a Sunday and ends on a Saturday). In particular, the due date for the pre-labs, as well as the open date for the in-labs and post-labs is when the first lab section starts. The close date for the post-labs is the start of Friday's lecture (the first lecture, if there are multiple lecture periods).
The various dates: open dates, due dates, and close dates, are listed on the lab due dates page.
Please note, however, that there are a number of rules that we will strictly follow:
The assignments tool does not handle due dates such as "at the end of your lab session" very well -- indeed, the due date is listed as 10 p.m. on Tuesdays. Note that we have a script that will test the assignment's due date against your lab date, so please be sure to follow the above due dates.
You can automatically request a lab extension if you are unable to complete your in-lab during the allotted time. This is done through the lab extension tool, which is accessible either via Collab or through the link in the Procedure section, above. Note that this only applies to the in-lab. The due date with the extension is the end of the day on Wednesday (i.e. 11:59 p.m.), regardless of your lab section, as this gives you a chance to go to the Wednesday evening office hours.
All assignments for this course will be submitted through the lab submission tool, which is accessible either via Collab or through the link in the Procedure section above. There is no check to make sure you have submitted all of the correct files -- on the 'Procedure' page (always at the top of the lab document), we clearly state which files should be submitted for each lab part. For example, for this in-lab, you should submit the following files for in-lab 1: lifecycle.questions.txt, vector.questions.txt, LifeCycle.h, LifeCycle.cpp, and TestLifeCycle.cpp.
Lastly, you should ensure that your program compiles before you submit it. This is an advanced programming class, and there is no reason why you should submit a program that does not compile. If you are having problems with your code, you should comment out parts so that it does compile -- you will receive more credit for a compilable program that has part of the code commented out than you would for a program that does not compile. See the compilation for hints as to how to get your code to compile.
Just to be clear: you will receive zero credit for a lab component which does not compile.
If you submit your assignment, and you realize you made a mistake (didn't submit all the files, etc.), you can resubmit your assignment. The date of submission is the date you re-submitted your assignment -- so if you resubmit your assignment after the due date to add one more file, the ENTIRE assignment will have the late submission date. We only look at the most recent submission. There is no penalty for a reasonable number of submissions (i.e., if you hit 100 or so, we will think you are hacking our servers).
Complete the exercise below, and submit the text file described there to the submission system.
For this lab you will be submitting your assignment electronically. Your submission is on the Friday of the week of the lab; the exact time is listed on the lab due dates page. Be sure to include your name, email ID, the date, and the name of the file in a banner comment at the beginning of each file you submit.
Download the two linked list files (list.h (src) and list.cpp (src)). Compile and run the program. The compile command is clang++ list.cpp. If you try to compile the list.h file, it won't work correctly.
Look at list.h, which is #include'd from list.cpp -- it contains the bodies of the methods, which is not the way that it is usually done (the bodies are typically in the .cpp file only). We normally only include in .h files just the declarations (i.e., prototypes) of classes, constants, function, etc., but not definitions of C++ methods (i.e. the bodies of the methods). However, when implementing template classes, this is something that is necessary to make the class compile successfully.
Look more closely at list.cpp. The line:
List<int> *l = new List<int>();declares (a pointer to) a List of integers, called l. A similar line, but with a different type, would create a list of something else. For example, consider the following line:
List<char> list2;This declares a (non-pointer) list of characters (this is not in the list.cpp file, by the way). Now all the methods in the List class will be available to both l and list2.
Write at least one question about something in this program. Put your question(s) in a text file called "postlab1.question.txt" and submit this to the submission system to the post-lab 1 assignment.